Crocking is a transfer of color from the surface of a colored fabric to an adjacent area of the same fabric or to another surface principally by rubbing action. Crockfastness is color fastness to rubbing (crocking). The improvement of crockfastness/colorfastness of dyed textile fabrics has been an ongoing problem in the textile industry. Attempts to resolve the problem have entailed additives during the dyeing process as well as post treatments.
For example, U.S. Pat. No. 4,531,946 discloses use of a fabric finish containing a reactive polyamine derivative in combination with a blocked urethane for cellulosic and cellulosic blends which have been dyed with disperse/naphthol or disperse/sulfur disperse/vat dye systems. U.S. Pat. No. 4,737,156 discloses use of cationic cellulose graft copolymers for improving dye fastness to a dyed textile substrate by post dye application (top-up). U.S. Pat. No. 4,740,214 discloses a pattern dyeing process wherein an anionic and a cationic component come into contact with each other when a dye solution is applied to a textile. An ionic interaction is stated to occur to form a water-insoluble dye-impermeable skin around individual dye droplets which then controls undesired migration of the dye. One of the components is applied to a textile material prior to application of the dye solution in a desired pattern and then the corresponding counter-ionic material is applied as a component of the dye solution.
Glyoxylated polyacrylamide-diallyldimethyl ammonium chloride copolymer (GPA) resins are known for use as dry strength and temporary wet strength resins for paper. U.S. Pat. No. 4,605,702, for instance, teaches the preparation of a wet strength additive by glyoxalating an acrylamide copolymer having a molecular weight from about 500 to 6000. The resulting resins have limited stability in aqueous solution and gel after short storage periods even at non-elevated temperatures. Accordingly, the resins are typically supplied in the form of relatively dilute aqueous solutions containing only about 5-10 wt % resin.
Co-filed U.S. Ser. No. 09/094,927 discloses the use of a mixture of (i) a cationic glyoxalated acrylamide-diallyldimethylammonium chloride wherein the mole ratio of glyoxal to acrylamide copolymer is between about 0.7:1 to about 0.1:1 and (ii) an aminopolyamide-epichlorohydrin polymer, in a weight ratio of about 0.5:1 to about 5:1, for improving crocking of a fabric.
Co-filed U.S. Ser. No. 09/094,900 discloses an improved method for improving crocking of a fabric by (a) fixing the fabric with a cationic charge prior to dyeing, (b) dyeing the fabric, (c) coating the dyed fabric with an anionic polymer, (d) drying the fabric, (e) coating the anionic polymer coated dyed fabric with a cationic polymer, and (f) drying the resulting fabric. When an anionic polymer coating is placed atop a fabric which is not cationic fixed before dyeing and then a cationic polymer mixture of (i) a cationic glyoxalated acrylamide-diallyl-dimethylammonium chloride wherein the mole ratio of glyoxal to acrylamide copolymer is between about 0.7:1 to about 0.1:1 and (ii) an aminopolyamide-epichlorohydrin polymer, in a weight ratio of about 0.5:1 to about 5:1, only small non-consistent improvements in crocking of a fabric occurred.
It is an object of this invention to provide a method for improving crocking of a dyed textile product.